TGantt

Source: source/classes/gantt.prg

Inherits from: TControl

TGantt is FiveWin's Gantt chart control for project scheduling and timeline visualization. It displays horizontal bars across a time-based grid, where each bar represents a task with its start and end dates. The control supports interactive mouse operations, month-day grid views, and dynamic recalculation.

Key DATA Members

DATA	Type	Default	Description
`aItems`	Array	`{}`	Array of TGanttItem objects
`nCellWidth`	Numeric	`28`	Width of each grid cell in pixels
`nCellHeight`	Numeric	`25`	Height of each grid cell in pixels
`nCols`	Numeric	`31`	Number of grid columns (typically days in month)
`nRows`	Numeric	`6`	Number of grid rows (tasks)
`lGridMonth`	Logical	`.F.`	Show month-day header grid
`bChange`	Block		Code block executed when an item is changed
`bPressed`	Block		Code block executed on item press
`nTopOffset`	Numeric	`5`	Top offset for grid rendering

Methods

Method	Description
`New( nTop, nLeft, nWidth, nHeight, oWnd, lBorder, lVScroll, lHScroll, nClrFore, nClrBack, bChange, bPressed, oLbx )`	Create a new TGantt control
`Redefine( nId, oWnd, nClrFore, nClrBack, bChange, bPressed, oLbx )`	Redefine from dialog resource
`AddItem( nRow, nStart, nEnd, nClrBack )`	Add a Gantt bar item to the specified row with start/end columns and background color
`AtItem( nRow, nCol )`	Get the TGanttItem at the specified grid position
`SetGridMonth( nRows )`	Switch to month-day header grid mode. nRows = number of weeks to display.
`ReCalculate()`	Recalculate grid dimensions and item positions after resizing
`GridMonth()`	Draw the month-day header labels
`Paint()`	Render the Gantt grid and all items
`Display()`	Begin paint, call Paint, end paint

TGanttItem

Each bar in the Gantt chart is represented by a TGanttItem object with the following properties:

Property	Type	Description
`nRow`	Numeric	Row position of the item
`nStart`	Numeric	Start column (typically day number)
`nEnd`	Numeric	End column (typically day number)
`nClrBack`	Numeric	Background color of the bar

Example: Project Plan Gantt Chart

#include "FiveWin.ch"

function Main()

   local oWnd, oGantt

   DEFINE WINDOW oWnd TITLE "Project Plan" SIZE 800, 400

   @ 10, 10 GANTT oGantt SIZE 760, 340 OF oWnd ;
      CHANGE { |oItem| MsgInfo( "Item changed: Row " + Str( oItem:nRow ) ) }

   // Configure month-day grid for a 4-week view
   oGantt:SetGridMonth( 4 )
   oGantt:nCols := 28

   // Add tasks (row, start_day, end_day, color)
   oGantt:AddItem( 1, 1,  5, CLR_HRED )
   oGantt:AddItem( 2, 3,  10, CLR_HBLUE )
   oGantt:AddItem( 3, 6,  18, CLR_HGREEN )
   oGantt:AddItem( 4, 12, 22, RGB( 255, 165, 0 ) )
   oGantt:AddItem( 5, 15, 28, CLR_HMAGENTA )

   ACTIVATE WINDOW oWnd CENTERED

return nil

Notes